Hi Mike. My questions relates more to jam bands, funk, jazz-rock, ... and mostly modal songs. When the guitarist plays a solo, I try to play more harmonically to fill the chords he doesn't play, or get a fatter yet quieter sound to support him. Same for horns. They are soloists by nature, so I mostly support them as usual. Now, what to do when the drummer takes his solo ? It tends to sound empty and it doesn't "flow" into the rest of the tune, if you know what I mean. I could pump the rhythm crazy, but then I may restrict him.